Sanding disc assembly



Oct. 10, 1967 w RlKER 3,345,785

SANDING DISC ASSEMBLY Filed Dec. '7, 1964 F/GZ F G. 5 F761 5 M M i 5 M INVENTOR. 1i 44 13 7 .uz (((a BY United States Patent 3,345,785 SANDING DISC ASSEMBLY Warren N. Riker, 138 E. Clinton Ave., Tenafly, NJ. 07670 Filed Dec. 7, 1964, Ser. No. 416,515

3 Claims. (Cl. 51-362) 7 ABSTRACT OF THE DISCLOSURE A disc sanding device 'for attachment to a source of rotary power having a resilient disc shaped member with a concave face thereon and a cup-shaped circular member into which the disc fits. The cup-shaped member has a sheet of abrasive material secured to its outer face and the disc drives the cup-shaped member by its frictional peripheral contact with the inner walls of the cup-shaped member as pressure is applied.

This invention relates to sanding disc devices for use in rotary sanding machines such as drill presses, hand electric drills, lathes, and the like.

Presently known sanding disc devices consist of a rigid or flexible circular member mounted in a source of rotary power and having a sheet of abrasive material secured thereto. The abrasive disc is generally bonded to the rigid or flexible circular member or held thereon by means of a cup-shaped washer and screw threaded into the arbor or shank of the sanding disc device. Where the abrasive is bonded to the disc it is difficult to remove and often difilcult to secure good adhesion to the disc. In those devices where the disc is held by means of the cup washer and screw, the substantial size of the washer necessary to hold the abrasive material somewhat reduces the effective surface of the disc. But more often, in use, the abrasive disc tears away from the cup washer fastening after a few moments of use thus ruining the abrasive disc and obviously interrupting the sanding operation.

Accordingly, it is an object of the present invention to provide a sanding disc device in which the application of the abrasive material to the supporting disc is greatly facilitated.

Another object of the present invention is to provide a sanding disc device in which the complete abrasive surface is available for sanding purposes.

Another object of the present invention is to provide an inexpensive abrasive carrying member which can be applied quickly and removed readily while at the same time insuring positive frictional engagement wth the supporting disc during the sanding operation.

A feature of the present invention is its use of a cup shaped support for the abrasive material.

Another feature of the present invention is its use of a concave resilient supporting disc for the abrasive material.

The invention consists of the construction, combination and arrangement of parts, as herein illustrated, described and claimed.

In the accompanying drawing, forming a part hereof is illustrated one form of embodiment of the invention, and in which:

FIGURE 1 is a view in perspective of a complete embodiment of a sanding disc device made in accordance with the present invention.

FIGURE 2 is a somewhat exploded vertical section taken on line 2-2 in FIGURE 1 on an enlarged scale.

FIGURE 3 is a view similar to FIGURE 2 in an assembled condition.

FIGURE 4 is a view similar to FIGURE 3 showing 3,345,785 Patented Oct. 10, 1967 the effects of the application of pressure during the sanding operation. v

FIGURE 5 is a fragmentary view in vertical section of a portion of the sanding disc device showing the manner in which the abrasive supporting cup is heldby the support disc.

FIGURE 6 is a view similar to FIGURE, 5 showing the relative positions of the parts upon the application of pressure.

5 Referring to the drawing, and particularly to FIG- URE 1, 10 indicates a disc sanding device having a cylindrical shank 11 extending therefrom. Theshank 11 is preferably made of steel and adapted to be engaged with a rotary power source (not shown).

The shank 11 is molded into the hub 23 of 'aresilient support disc 12 which may be made of rubber, neoprene, or some other suitable material. The support disc 12 is formed with a concave outer face 13 and tapers graduallyto its outer edges as indicated at 14. v

A circular cup shaped member 15, best shown in FIG: URES 1, 2, 3, and 4 is received upon the circular sup port disc 12. The cup shaped member 15 is further pro vided with a sheet of abrasive material 20 which may be cemented or bonded thereto. Alternately, the abrasive material may be molded directly into the bottom portion 16 of the cup shaped member 15, without departing from the spirit of the present invention.

' The cup shaped member 15 is preferably made of some inexpensive plastic material such as polyethylene,"

nylon, or the like. In addition, the cup shaped member has an upstanding peripheral wall 17 which is undercut adjacent the bottom 16 of the cup shaped member as indicated at 18 in FIGURES 2 thru 6. The undercut portion 18 provides a radial groove which is of a size to receive the peripheral portion of the support disc 12.

When the cup shaped member 15 is applied to the support disc 12, the tapered portion 19 of the upstanding wall 17 guides the support disc downwardly and into the groove 18. The cup shaped member 15 is thus readily snapped over the edges of the support disc 12 into the position shown in FIGURE 3. The disc sanding device is then ready for use.

When pressure is applied to the'disc sanding device 10 in the manner shown in FIGURE 4 and indicated by the arrow 21, a resilient support disc 12 is flattened against the inner surface 22 of the cup shaped member 15. Air is thus expelled from between the support disc 12 and the cup shaped member 15. The outside diameter of the support disc 12 is increased so that the periphery of the support disc is forced tightly into the groove 18 in the manner shown in FIGURES 4 and 6. As a result of the application of pressure to the disc sanding device, during the normal use of said device, frictional engagement and the vacuum cup operation of the concave face 13 of the supporting disc 12, provide a very positive connection between the supporting disc 12 and the cup shaped member 15. This connection is sufiicient to enable the sanding operation to continue without any slip between the cup shaped member 15 and the supporting disc 12.

When the abrasive sheet 20 is worn out, it may be replaced by stripping the cup shaped member 15 off the supporting disc and snapping a new one in place. This stripping operation is easily accomplished by grasping the upstanding peripheral wall and pulling it away from the resilient support disc 12. g

It will be apparent that the abrasive portion of the sanding disc device can be changed without recourse to tools and in a minimum amount of time. In addition, various grades of abrasives can be applied to the sanding disc in the course of the finishing operation.

-While the foregoing description and the drawing have beenvconfinedtothe. use of abrasive material, it will be apparent that the present device can be used for buffing, wire brushing, waxing and the like. In the further uses of the present device it is merely necessary to substitute the appropriate material for the abrasive sheet 20 on the outer face of the bottom 16 of the cup shaped member 15.

Also, while the foregoing description and drawing have been confined to a disc having a shallow concave shape, it is apparent that the shape can be readily changed to a conical shape (either pointed or truncated) or semi-spherical without departing from the spirit of the present invention.

Having thus fully described the invention, what is claimed as new and desired to be secured by Letters Patent of the United States, is: 1.. A disc sanding device comprising a resilient discshaped support member, a cylindrical shank axially carried by the support member and normal thereto, a concave face on the support member opposite the shank, a circular member having a substantially planar outer face and peripheral flange thereabout, said member being detachably mounted upon the support member and overlying the concave face with the flange in driving frictional contact with the outer periphery of the support member and a sheet of abrasive material secured to the outer face of the circular member.

2. A disc sanding device comprising a resilient discshaped support member, comprising an outwardly tapered body portion and an upstanding central hub, a cylindrical shank axially carried by the support member hub and normal thereto, a concave face on the support member opposite the shank, a circular member having a substantially planar outer face and a peripheral flange thereabout, said member being detachably mounted upon the support member and overlying the concave face with the flange in driving frictional contact with the outer periphery of the support member and a sheet of abrasive material secured to the outer face of the circular member.

3. A disc sanding device comprising a resilient discshaped support member, comprising a radially outwardly tapered body portion and an upstanding central hub, a cylindrical shank axially carried by the support member hub and normal thereto, a concave face on the support member opposite the shank, a cup-shaped circular member having a substantially planar outer face detachably mounted upon the support member and overlying the concave face comprising a bottom and an upstanding Wall integral with the bottom and extending peripherally thereof, a radially facing groove in the inner surface of the upstanding wall adjacent the bottom thereto detachably receiving in driving frictional contact, the outer pheriphery portion of the support member and a sheet of abrasive material secured to the outer surface of the bottom of the cup-shaped member. 1

References Cited UNITED STATES PATENTS 2,581,567 1/1952 Wiley 51-358 2,991,596 7/1961 Walters 51376 3,092,937 6/ 1963 Tocci-Guilbert 51-377 3,174,258 3/1965 Kenny 51358 X ROBERT C. RIORDON, Primary Examiner.

D. G. KELLY, Examiner. 

1. A DISC SANDING DEVICE COMPRISING A RESILIENT DISCSHAPED SUPPORT MEMBER, A CYLINDRICAL SHANK AXIALLY CARRIED BY THE SUPPORT MEMBER AND NORMAL THERETO, A CONCAVE FACE ON THE SUPPORT MEMBER OPPOSITE THE SHANK, A CIRCULAR MEMBER HAVING A SUBSTANTIALLY PLANAR OUTER FACE AND A PERIPHERAL FLANGE THEREABOUT, SAID MEMBER BEING DETACHABLY MOUNTED UPON THE SUPPORT MEMBER AND OVERLYING THE CONCAVE FACE WITH THE FLANGE IN DRIVING FRICTIONAL CONTACT WITH THE OUTER PERIPHERY OF THE SUPPORT MEMBER AND A SHEET OF ABRASIVE MATERIAL SECURED TO THE OUTER FACE OF THE CIRCULAR MEMBER. 